title: The added value of impedance-pH monitoring to Rome III criteria in distinguishing functional heartburn from non-erosive reflux disease.
abstract: BACKGROUND
  Functional heartburn is defined by Rome III criteria as an endoscopy-negative condition with normal oesophageal acid exposure time, negative symptom association to acid reflux and unsatisfactory response to proton pump inhibitors. These criteria underestimated the role of non-acid reflux.
  
  
  OBJECTIVE
  To assess the contribution of impedance-pH with symptom association probability (SAP) analysis in identifying endoscopy-negative patients with reflux disease and separating them from functional heartburn.
  
  
  METHODS
  Consecutive endoscopy-negative patients treated with proton pump inhibitors (n=219) undergoing impedance-pH monitoring off-therapy were analysed. Distal acid exposure time, reflux episodes, SAP and symptomatic response to proton pump inhibitors were measured.
  
  
  RESULTS
  Based on impedance-pH/SAP, 67 (31%) patients were pH+/SAP+, 6 (2%) pH+/SAP-, 83 (38%) hypersensitive oesophagus and 63 (29%) functional heartburn. According to pH-metry alone/response to proton pump inhibitors, 62 (28%) were pH+/SAP+, 11 (5%) pH+/SAP-, 61 (28%) hypersensitive oesophagus and 85 (39%) functional heartburn. In the normal-acid exposure population the contribution of impedance-pH/SAP compared to pH-metry alone/response to proton pump inhibitors in identifying patients with reflux disease and functional heartburn resulted to be 10%. In patients with abnormal-acid exposure, the contribution of impedance-pH/SAP increased by 3%.
  
  
  CONCLUSIONS
  Comparing impedance-pH testing with pH-metry alone plus the response to proton pump inhibitor therapy demonstrated that the latter ones cause underestimation of reflux disease patients and overestimation of functional heartburn patients.
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, University of Genoa, Genoa, Italy; Division of Gastroenterology, IRCCS Istituto Clinico Humanitas, Milan, Italy. edoardo.savarino@unige.it
authors.forename: Edoardo
authors.initials: E
authors.lastname: Savarino
authors.forename: Elisa
authors.initials: E
authors.lastname: Marabotto
authors.forename: Patrizia
authors.initials: P
authors.lastname: Zentilin
authors.forename: Marzio
authors.initials: M
authors.lastname: Frazzoni
authors.forename: Giorgio
authors.initials: G
authors.lastname: Sammito
authors.forename: Daria
authors.initials: D
authors.lastname: Bonfanti
authors.forename: Luca
authors.initials: L
authors.lastname: Sconfienza
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Assandri
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Gemignani
authors.forename: Alberto
authors.initials: A
authors.lastname: Malesci
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Savarino
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015992:Body Mass Index; D003937:Diagnosis, Differential; D017097:Electric Impedance; D016099:Endoscopy, Gastrointestinal; D050782:Esophageal pH Monitoring / Q000592:standards*; D005260:Female; D005764:Gastroesophageal Reflux / Q000175:diagnosis* / Q000378:metabolism; D006356:Heartburn / Q000175:diagnosis* / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D055815:Young Adult